1. Field of the invention
This invention relates to internetwork communications systems structured to provide guaranteed communications between and among various financially-related devices and systems and the users thereof, preferably via modularized systems, and to methods for using the same. More specifically, this invention relates to a communications structure linking remote data, services, and branch offices, where the data typically is derived from such diverse sources as long-term databases and real-time transactions.
2. The State of the Art
Internetworking is the providing of complete connectivity with, and sometimes among, organizational members. In an organization, especially a large organization with multiple offices located at separate physical plants, communication of data is facilitated by an internetwork. Internetworking, and the related hardware and software, are per se well-known; e.g., Miller, Mark A., Internetworking (New York: M&T Books div. MIS:Press, 1995), and Martin, James, Enterprise Networking (Upper Saddle River, New Jersey: Prentice Hall PTR, 1996), the disclosures of which are incorporated herein by reference.
As the term internetwork implies, an internetwork generally comprises a number of smaller networks, typically on local scales, which are interconnected to each other. These smaller networks, which may be Local Area Networks (LANs), typically provide a communications network by which local computers (e.g., from personal computers, including workstations and/or dumb terminals, to minicomputers, and to main frames) intercommunicate. LANs oftentimes utilize phone lines (e.g., twisted pairs) to enable local computers to share data, send messages (such as e-mail), utilize pooled facilities (such as printer pools and modem pools, sets of similar hardware for use by all on the local network), and access third party or other exterior resources; LANs can also incorporate infrared (IR) and radio frequency (RF) communications devices by which remote users are provided access. There are four major well-known LAN architectures: Ethernet, token ring, ARCNET, and FDDI (fiber distributed data interface); as well as related derivative architectures (e.g. token bus).
The LANs are often connected to each other by a Wide Area Network (WAN). Wide area network data transmission links are most often implemented using conventional telecommunications facilities, such as ordinary telephone circuits. In the United States, these services are provided by "telecommunications common carriers"; in other countries these services are often provided by governmental postal, telephone, and telegraph (PTT) administrations. WAN data links are typically used to provide point-to-point connections between pairs of systems (such as LANs) typically located some distance from each other.
In both LANs and WANs, data are transferred much like letters are delivered by the postal service: the data is encapsulated or otherwise associated with addressing information that directs the data to a particular location. The data packet, or the format in which it is being sent, is typically called the frame. In these networks, there are communications protocols and routing information to assure data gets to its proper destination. As data is sent from a local user up the network (e.g., through the LAN to the WAN), additional data is added to the primary data being sent. The additional data includes routing information to direct the primary data to its intended recipient; as such, the frame includes the primary data and all of the additional data added along the way. As the frame data is received at the destination LAN, and sent to the intended recipient, the additional data is stripped from the primary data as the frame moves down through the internetwork, and finally the primary data is received at the desired destination without all of the routing and control data associated with the transmission.
Major problems occur with any communications system when it becomes necessary to compensate for periods of high volume traffic and/or period of catastrophe in which the system is disrupted. One method for compensating in the case of a catastrophe is described in co-pending application Ser. No. 306,382, filed Sep. 15, 1994, and titled "System For Enhanced Financial Trading Support", the disclosure of which is incorporated herein by reference in its entirety; in general, a secondary system normally designed for a given task (e.g., not related to trading, market services, or the like) is changed to operate as fit were a primary system designed for that task (i.e., specifically related to trading, market services, and the like) in the event of an emergency. Another problem yet to be addressed occurs when the physical portions of the internetwork fail, and especially where the failed component is part of the central communications backbone. Standard design practice for internetwork engineering (e.g., as described by Miller and by Martin, supra) is to engineer a 30% excess capacity into the hardware. While a 30% increase in bandwidth may likely compensate for some periods of high volume data traffic, it is clearly inadequate when, for example, one of the routers fails. This amount of excess capacity is also clearly inadequate when it is desirable to replace a router or other element of the internetwork, or when it is desirable to test a new component, because the data traffic normally handled by that component has no other path to travel.